Dynamic cooling of print media in a radiant dryer

Abstract

Systems and methods provide targeted cooling for portions of print media during a radiant drying process. One embodiment comprises a radiant dryer and a control system. The radiant dryer includes a radiant energy source within an interior of the radiant dryer that dries a colorant onto a continuous-form medium. The radiant dryer further includes a plurality of independently actuated cooling jets within the interior that apply a cooling gas to the medium. The control system determines regions on the medium where the colorant is at risk of overheating, and directs the cooling jets to apply the cooling gas to the regions.

We claim: 
     
       1. A method comprising:
 drying a colorant applied onto a continuous-form paper using a radiant energy source within an interior of a radiant dryer; 
 identifying a colorant applied to a region on the paper; 
 identifying a radiant energy absorption profile for the colorant; 
 determining a risk of overheating for the region based on the identified colorant and the radiant energy absorption profile for the identified colorant; and 
 directing a plurality of independently actuated cooling jets within the interior of the radiant dryer to apply a cooling gas to the region. 
 
     
     
       2. The method of  claim 1  wherein:
 determining regions where the colorant is at risk further comprises:
 determining an amount of energy absorbed by the region based on the radiant energy absorption profile of the identified colorant and a radiant emission profile of the radiant energy source; and 
 
 directing the plurality of cooling jets further comprises:
 varying an application of the cooling gas to the region based on the amount of energy absorbed. 
 
 
     
     
       3. The method of  claim 1  wherein:
 determining regions where the colorant is at risk further comprises:
 identifying a plurality of colorants applied to the region on the paper; 
 identifying a composite absorption profile for the plurality of colorants; and 
 determining the risk of overheating for the region based on the identified colorants and the radiant energy absorption profile for the identified colorants. 
 
 
     
     
       4. The method of  claim 1  wherein:
 the plurality of cooling jets are organized as a 2-dimensional array of independently actuated cooling jets within the interior of the radiant dryer; and 
 directing the plurality of cooling jets further comprises:
 identifying a subset of the 2-dimensional array of cooling jets that are proximate to the region; and 
 directing the subset of cooling jets to apply the cooling gas to the region. 
 
 
     
     
       5. The method of  claim 4  wherein:
 directing the plurality of cooling jets further comprises:
 varying at least one of an activation time, a flow rate, and a velocity of the cooling gas for the subset of cooling jets based on the risk of overheating for the region. 
 
 
     
     
       6. A non-transitory computer readable medium embodying programmed instructions executable by a processor, the instructions operable to direct the processor to:
 dry a colorant applied onto a continuous-form paper using a radiant energy source within an interior of a radiant dryer; 
 identify a colorant applied to a region on the paper; 
 identify a radiant energy absorption profile for the colorant; 
 determine a risk of overheating for the region based on the identified colorant and the radiant energy absorption profile for the identified colorant; and 
 direct a plurality of independently actuated cooling jets within the interior of the radiant dryer to apply a cooling gas to the region. 
 
     
     
       7. The non-transitory computer readable medium of  claim 6  wherein:
 instructions to determine regions where the colorant is at risk further comprise instructions to:
 determine an amount of energy absorbed by the region based on the radiant energy absorption profile of the identified colorant and a radiant emission profile of the radiant energy source; and 
 
 instructions to direct the plurality of cooling jets further comprise instructions to:
 varying an application of the cooling gas to the region based on the amount of energy absorbed. 
 
 
     
     
       8. The non-transitory computer readable medium of  claim 6  wherein:
 instructions to determine regions where the colorant is at risk further comprise instructions to:
 identify a plurality of colorants applied to the region on the paper; 
 identify a composite absorption profile for the plurality of colorants; and 
 determine the risk of overheating for the region based on the identified colorants and the radiant energy absorption profile for the identified colorants. 
 
 
     
     
       9. The non-transitory computer readable medium of  claim 6  wherein:
 the plurality of cooling jets are organized as a 2-dimensional array of independently actuated cooling jets within the interior of the radiant dryer; and 
 instructions to direct the plurality of cooling jets further comprise instructions to:
 identify a subset of the 2-dimensional array of cooling jets that are proximate to the region; and 
 direct the subset of cooling jets to apply the cooling gas to the region. 
 
 
     
     
       10. The non-transitory computer readable medium of  claim 9  wherein:
 instruction to direct the plurality of cooling jets further comprise instructions to:
 vary at least one of an activation time, a flow rate, and a velocity of the cooling gas for the subset of cooling jets based on the risk of overheating for the region. 
 
 
     
     
       11. An apparatus comprising:
 a radiant dryer of a printing system, the radiant dryer including:
 a radiant energy source within an interior of the radiant dryer that is operable to dry a colorant applied onto a continuous-form paper; and 
 a plurality of independently actuated cooling jets within the interior of the radiant dryer that are operable to apply a cooling gas to the paper and the colorant applied thereto; and 
 
 a control system operable to identify a colorant applied to a region on the paper, to identify a radiant energy absorption profile for the colorant, to determine a risk of overheating for the region based on the identified colorant and the radiant energy absorption profile for the identified colorant, and to direct the cooling jets to apply the cooling gas to the region. 
 
     
     
       12. The apparatus of  claim 1  wherein:
 the control system is further operable to determine an amount of energy absorbed by the region based on the radiant energy absorption profile of the identified colorant and a radiant emission profile of the radiant energy source, and to vary an application of the cooling gas to the region based on the amount of energy absorbed. 
 
     
     
       13. The apparatus of  claim 1  wherein:
 the control system is further operable to identify a plurality of colorants applied to the region on the paper, to identify a composite absorption profile for the plurality of colorants, and to determine the risk of overheating for the region based on the identified colorants and the radiant energy absorption profile for the identified colorants. 
 
     
     
       14. The apparatus of  claim 1  wherein:
 the plurality of cooling jets are organized as a 2-dimensional array of independently actuated cooling jets within the interior of the radiant dryer; and 
 the control system is further operable to identify a subset of the 2-dimensional array of cooling jets that are proximate to the region, and to direct the subset of cooling jets to apply the cooling gas to the region. 
 
     
     
       15. The apparatus of  claim 14  wherein:
 the control system is further operable to vary at least one of an activation time, a flow rate, and a velocity of the cooling gas for the subset of cooling jets based on the risk of overheating for the region.